Make <asm-generic/statfs.h> suitable for 64-bit platforms.

At the moment, 64-bit platforms (other than Alpha) are all redefining
things for themselves instead of using <asm-generic/statfs.h>.

As is ARM, since it has special requirements w.r.t. padding.

Make <asm-generic/statfs.h> more generic, and they can use it directly.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

arch/alpha/include/asm/statfs.h

 #ifndef _ALPHA_STATFS_H
 #define _ALPHA_STATFS_H
 
+/* Alpha is the only 64-bit platform with 32-bit statfs. And doesn't
+   even seem to implement statfs64 */
+#define __statfs_word __u32
+
 #include <asm-generic/statfs.h>
 
 #endif

include/asm-generic/statfs.h

@@ -6,33 +6,64 @@
 typedef __kernel_fsid_t	fsid_t;
 #endif
 
+/*
+ * Most 64-bit platforms use 'long', while most 32-bit platforms use '__u32'.
+ * Yes, they differ in signedness as well as size.
+ * Special cases can override it for themselves -- except for S390x, which
+ * is just a little too special for us. And MIPS, which I'm not touching
+ * with a 10' pole.
+ */
+#ifndef __statfs_word
+#if BITS_PER_LONG == 64
+#define __statfs_word long
+#else
+#define __statfs_word __u32
+#endif
+#endif
+
 struct statfs {
-	__u32 f_type;
-	__u32 f_bsize;
-	__u32 f_blocks;
-	__u32 f_bfree;
-	__u32 f_bavail;
-	__u32 f_files;
-	__u32 f_ffree;
+	__statfs_word f_type;
+	__statfs_word f_bsize;
+	__statfs_word f_blocks;
+	__statfs_word f_bfree;
+	__statfs_word f_bavail;
+	__statfs_word f_files;
+	__statfs_word f_ffree;
 	__kernel_fsid_t f_fsid;
-	__u32 f_namelen;
-	__u32 f_frsize;
-	__u32 f_spare[5];
+	__statfs_word f_namelen;
+	__statfs_word f_frsize;
+	__statfs_word f_spare[5];
 };
 
+/*
+ * ARM needs to avoid the 32-bit padding at the end, for consistency
+ * between EABI and OABI 
+ */
+#ifndef ARCH_PACK_STATFS64
+#define ARCH_PACK_STATFS64
+#endif
+
 struct statfs64 {
-	__u32 f_type;
-	__u32 f_bsize;
+	__statfs_word f_type;
+	__statfs_word f_bsize;
 	__u64 f_blocks;
 	__u64 f_bfree;
 	__u64 f_bavail;
 	__u64 f_files;
 	__u64 f_ffree;
 	__kernel_fsid_t f_fsid;
-	__u32 f_namelen;
-	__u32 f_frsize;
-	__u32 f_spare[5];
-};
+	__statfs_word f_namelen;
+	__statfs_word f_frsize;
+	__statfs_word f_spare[5];
+} ARCH_PACK_STATFS64;
+
+/* 
+ * IA64 and x86_64 need to avoid the 32-bit padding at the end,
+ * to be compatible with the i386 ABI
+ */
+#ifndef ARCH_PACK_COMPAT_STATFS64
+#define ARCH_PACK_COMPAT_STATFS64
+#endif
 
 struct compat_statfs64 {
 	__u32 f_type;
@@ -46,6 +77,6 @@ struct compat_statfs64 {
 	__u32 f_namelen;
 	__u32 f_frsize;
 	__u32 f_spare[5];
-};
+} ARCH_PACK_COMPAT_STATFS64;
 
 #endif